Glandless pump



oct. 1o, 195o R. L L, MOINEAU 2,525,265

GLANDLESS PUMP Filed June 18, 1946 2 Sheets-Sheet 1 IN VEN TOR.

33 fev/E Jos-PH lau/.s /Vo//vfam BY`M ATTORNEYS.

Oct. 10, 1950 R. J. L. MolNEAu GLANDLESS PUMP Filed June 18. 1946 2Sheets-Sheet 2 N VE NTOR. 001.5 [ifa/N540.

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Patented Oct. 10, 1950 2,525,265 l GLANDLEss PUMP en Joseph LouisMoineau, Paris, France; Adele Moineau, administratrix of said Ren JosephLouis Moineau, assignor to Robbins & Myers, Inc., Springfield, Ohio, acorporation of Chio Application June 1s, 1946, serial N6. 677,611 InFrance September 13, 1945 1 This invention relates to a glandless pumpand particularly to a pump operating on the principles disclosed andclaimed in my U. S. Patent.

No. 1,892,217 dated December 27, 1932. In that patent I have disclosed apump comprising a stator and a rotor having respectively internal andexternal helical threads. The stator element always has one thread morethan the rotor element; for example, the stator might have a doublethread and the rotor a single thread, or the stator might have a triplethread and the rotor a double thread. As pointed out in that patent, inoperation there is a relative rolling motion of the rotor with respectto the stator; thus if the stator is fixed, the rotor will roll aroundtheinside oi' the stator, while if the roto-r is fixed, the stator willroll around the outside of the rotor.

I have discovered that it is possible, by combining two pairs of rotorsand stators in a certain manner, to achieve a number of advantages whichare not found in ordinary or conventional pumps; and itis therefore anobject of my invention to provide a pump comprising one or more pairs ofrotors and stators combined in such a manner that end thrust is entirelyeliminated. It'

isa further object of my invention to provide such a pump in whichstuffing boxes or packing glands are entirely eliminated. It is thus anancillary object of my invention to provide a pump adapted to thepumping of fluids. such as acids, which will deleteriously affect theconventional stufling box or packing gland, but which can be pumpedthrough my novel pumps without ill effects.

These and other objects of my invention which will be pointed out inmore detail hereinafter or which will be apparent to one skilled in the'art upon reading these specications, I accomplish by that certainconstruction and arrangement of parts of `which I shall now describecertainiexemplary embodiments.

Reference may be had to the drawings forming a part hereof and in whichFigs. 1 and 2 are diagrams which will assist in understanding principlesof operation of the pump.

. Fig. 3 is a longitudinal cross sectional view of a pump according tomy invention.

"Fig, 4 is a cross sectional view `taken line 4 4 of Fig. 3.

Figljis a longitudinal cross sectional view of a modiiication thereof. y

j Flgl` 6 is a perspectiveview oi still another form on the 10 Claims.(Cl. 103-4) Fig. rI is a cross sectional view line 1-1 of Fig. 6.

Fig. 8 is a cross sectional view on the line 8-8 taken on the of Fig. 9of a pump comprising a single set of v pumping elements, with a drivehaving no pumping function.

Fig. 9 is a cross sectional view taken on the line 9 9 of Fig. 8.

A study of my above mentioned patent will assist materially inunderstanding the present invention. `As indicated diagrammatically inFig. 1, the mechanism comprises tw'o groups of internal and externalgear members with parallel axes. These elements are represented in Fig.1 by their pitch circles. One group comprises two elements. one rollingwithin the other, the external element being represented by its pitchcircle C1, having its center at Oi and having a diameter D, and theinternal element being represented by the circle Cz, having its centerat O2 and having a ,diameter d. The second group also comprises twoelements, one rolling within the other. Their pitch circles areindicated respectively at Ca and C4 having their centers at 0a and O4respectively, and having respectively the same diameters D and d asthose of the first group.

Let it now be assumed that the internal elements i. e. those having thepitch circles C2 and C4 are rigidly connected as, for example, by a rodR in such manner that the points of tangency of their pitch circles C2and C4 with the pitch circles C1 and C: are in the same angularpositions. In Fig. 1, these points of tangency areindicated at a and b.

If now, one of the groups of gear members (C1 and Cz) is driven in sucha way that C1 is fixed, the circle C2 will roll on the interior surfaceof C1 without slipping. The other group (C3 and C4) ls driven in such away that the external element C: is caused to move in circulartranslation (without axial rotation) in the path denoted by the circleC5, having its center at O1 with the internal element C4 rolling withinthe element Ca without slipping.

It is demonstrable that if C2 turns in the directlon of the arrow firolling so that the point of contact is displaced in the oppositedirection, the member C1 remaining fixed, the circle C4 will roll withinthe circle C: in like manner and in the same direction provided that.(l) the circle C3 is given a circular translation in the path C5 and inthe direction of the arrow f2 (same direction as f1) and (2) the angle y(position angle of the circle Cs) bears a constant relation to the angle:c (position angle of the circle Ca). The angle :c represents the anglecovered by the point of contact of Cz with C1 from the point indicatedat a to the point indicated at a1. vThe point on the circle C2 at a hasduring this movement moved to the position a2 so that the arc aai isequal to the arc azar, and the angles which subtend these arcs, will berelated as:

Thus, the result'of driving two gearing elements by two other gearingelements having equal pitch circles, transforms a uniform circulartranslation into a, uniform rotation, or vice versa, the relationbetween the angular speeds being equal to The particular gears used maybe of any kind and even different from each other, providing that theyhave equal base circles. If the gears are of the type disclosed in myabove mentioned patent, then one or both pairs of gears may act aspumping elements.

Fig. 2 shows diagrammatically some profiles which may be used. Theseprofiles indicated at P1 and P2 are hypocycloids of the pitch circles Ceand C1. The external element Cs has one more thread than the internalelement C1. In this case, the number of threads is respectively 3 and 2,and in general, if n is the number of teeth of the internal element,then' d D-d-"n-I-l-n- Thus, in Fig. 2 we have nso that Referring to Fig.3, if the elements II) and II constitute a pump or compressor, they canbe driven by a gearing I2, I3 which could be of any type, helical ornot, and having any number of teeth, provided they have the same pitchcircles as those of the gears I0, II.

Instead of using conventional gearing for this drive it is possible touse another pair of pump elements which are in effect gears. Thisarrangement is illustrated in Figs. 3 and 4 where I have shown amulti-cylinder` pump having four pairs of pump elements driven byanother four pairs of pump elements. The pump elements are connected insets'as seen in Fig. 3 and equally distributed around the central axisof the pump. as seen in Fig. 4. The four pairs of gears I2, I3 areconnected together in a spider like mounting Il, mounted'by means ofbearings I5 on a crank shaft I6. The members II and I3 of the sets ofpump elements are rigidly connected together by the bent hollow shaftswhich act as cranks having an eccentricity equal to that of the crankshaft. I6. Because of the connections described, when rotation isimparted to the crank shaft I6, the members I2 will be given a circulartranslation but will not be permitted to rotate.

From the foregoing, it will be clear` that as the assembly indicatedvgenerally at Il follows the circular translation about the central axisof the pump, the cranked hollow shafts 20 will be caused to rotate andthe members I3 and II will roll respectively within the elements I0 andI2.

'I'he elements I2, I3 have a helical thread of opposite hand from thatof the members I0 and II so that the fluid being pumped entering theintake port at 2|, will be divided. That portion being pumped by theelements I0, II, passes through these gears to the discharge port 22; atthe same time, that portion being pumped by the elements I2, I3, passesto the right through c. the space between the sleeve I1 and the hollowshaft 20, is pumped toward the right by the elements I2, I3 into thechamber I4a. From here it passes back toward the left through the ghollow shaft 20 and joins that portion which is being pumped by themembers I0, II, both portions passing out through the port 22. In Figure3 the sleeve I1 is shown as a piece of rigid tubing mounted betweendiaphragm members I8 and I9.

The members I8 and I9 having to contend with considerable pivotal actionresulting from thc orbital movement have to be made of a thickrubber-like material. It would, of course, be possible for the parts I1,I8 and I9 to be constituted of a resilient material'molded in a singlepiece. The space between the sleeve I1 and the hollow offset shafting 20contains liquid under suction pressure moving in the direction of thearrows from left to right between the shaft 20 and sleeve I1. A study ofFig. 3 in connection with the foregoing description will demonstratethat in this pump, end thrust is entirely eliminated except for thatresulting from the passage of fluid through the hollow shaft 20, andthat the pump requires no packing glands or stuillng boxes whatever.

A variant is shown in Fig. 5 in which as above, there are four sets ofpumping elements, but both sets are flxed. The rotors are driven by acentrally disposed helical gearing, which in this case functions simplyas a gear and not as a pump. The stators 23 are all fixed in the housingrelative to each other and each pair of axially aligned rotors 24 areconnected by the crank portions 25 which are provided with an internalhelical gear element 26. The four elements 26 each roll in externalelements 21 and the four members 21 are carried in a spider arrangementabout a central bearing 28. The drive shaft 29 has a central crankportion 30 by means of which the assembly of four gear pairs 26, 21 isgiven a circular translation, whereby the cranks 25 are caused torotate, driving the rotors 2| of the eight pumping pairs. Since themembers 26, 21 donot have a pumping function, the length of thesemembers will preferably be equal to at least a fraction of the pitch ofa gear member equal to said pitch divided by the number of threads ofsaid member, as pointed out in my above mentioned patent. In fact themembers 26, 21 could be gears of any type and having any desired numberof teeth provided the relationships above mentioned obtain. This pumphas a completely balanced end thrust, since fluid entering the inletport is pumped outwardly through all eight pumping pairs into themanifolds 32 from which it passes to the exhaust port 33. It is alsopossible by reversing the rotation of the mechanism to have the fluidenter port 33 and discharge through port 3|. The shaft 29 is enclosed byfluid tight tubes 34 which are either wholly flexible or are rigid innature and are then fastened at each end by means of flexiblebellows-like members 36 and 36, so that again the pump of Fig. 5requires no packing glandsor "atrasos stumng boxes. In the embodiment ofFig. 5, the gears 26, 21 may be compared, as to their driving functions,to the members i2, |30! Iiig.v 3.

In Figs. 6 and 7, I have shown avcommercial embodiment oi' theprinciples described above in which there is a single set oi pumpingelements. The external element 40 is fixed in the housing 4I and theinternal element 42 will roll around the inside 4of the member 40. Theinternal member 42 is fastened to or is integral with the internalmember 43 of the other pair of pumping elements and the members 42 and43 are off-set to provided the necessary cranking action. The members 42and 43 are provided with an internal iluid passageway 44 extending fromthe exterior end of member 42 to the exterior end of member 43. Theexternal element 45 cooperating with the internal element 43 has abearing indicated generally at 46 in the cup like element 41. The member41 is driven by the motor 48; and there it should be noted that the axisof the bearing 46 is eccentric with respect to the motor axis s o thatthe member 41 rotates in a circular path about the motor axis. Since theexternal element 45 is xed in the member 49 which has its bearing at 46and since the member 49 is prevented from rotation by the sleeve 50 andthe diaphragms 5|, it will be clear that the member 45 will betranslated in a circular path without rotation. Ifthe relationshipsdescribed above are observed, the portion 43 will roll around the insideof the member 45 while the portion 42 rolls around the inside of thefixed element 40. Fluid entering the intake port 52 is pumped toward thetop by the elements 40, 42 and toward the bottom of the elements 43, 45.The portion of the iluid pumped by the elements 43, 45 is returned tothe top through the bore 44 and all the fluid emerges at the exhaustport 53.

In Figs. 8 and 9, I have illustrated a modified construction in whichthere is only a single pair oi.' pumping elements, and the driveelements are not even gears, although they produce the correct motionrequired for the pumping elements.

The pumping elements are indicated at 60 and 6|, the element 60 beingfixed in the housing 63.

member 6| is provided with the crank member 65 as was the case in allthe other examples. As a drive for the member 6|, I have provided the'member 66 mounted on a drive shaft B1, and having an internal circularbearing cup 68 which is eccentric to the shaft 61.

In the cup 68, I-mount a circular block 69, having two slots at rightangles to each other and at different depths, as shown at and 1I.Cross-heads 12 and 13 ride in these slots and are provided with bearingsockets 14 and 15, in which ride the pins 16 and 11 which are integralbut eccentric to each other, and are connected to the crank 65. Theblock 69 is held against 4axial rotation by the universal rods 18 asshown.

As the shaft 61 rotates, the cup 68 moves in a circular path because ofits eccentricity, and the block 69 is carried ina circular path withoutrotation because of the members 18. The parts 10, 1|, 12, 13, 14, 15,16, and 11 function in the same manner as, for example, the members I2,I3 of Fig. 3. They can, in fact, be considered as cross sectionalelements of a pair of members such as i2, I3, taken a quarter statorpitch length apart.

From the foregoing description, it will be understood that I haveprovided a glandless pump,

balanced against end thrust'and also dynamically balanced in rotation bythe counterweight 54 (see Fig. 7) .v It will be clear-that numerousmodiilcations may be made without departing` from the spirit of myinvention and that I dovnot intend to limit myself except as pointed outin the claims which follow.

For convenience and clarity in the claims:

(1) The term "gear pair" means an internal and an external khelicalygear in meshing relation, wherein the external gear has one more threadthan the internalsear, and the diameters of the pitch circles of saidgears are in proportion to the number oi' threads;

(2) The term "gear set means two gear pairs, the internal gears of whichare interconnected;

(3) The term pumping gear pair" means a gear pair which has a pumpingfunction;

(4) The term "driving gear pair means a gear pair which induces movementin another gear pair, and which may or may not have a pumping function.

Havingnew fully described my invention, what I claim as new and desireto secure by Letters Patent is:

1. A gear train comprising at least two gear pairs the axes of the gearsin said pairs being parallel, the pitch circles of the external gearsbeing equal and the pitch circles of the internal gears being equal, andsaid internal gears of the respective gear pairs being rigidly connectedtogether so that their orientation with respect to theirrespectiveexternal gears is the same, the external gear of one of saidpairs being fixed, and means for imparting to the external gear of theother of said pairs a circular translational movement.

2. A mechanism according to claim 1 in which one of said gear pairs is apumping gear pair.

3. A mechanism according to claim 1 in which both of said gear pairs arepumping gear pairs.

4. A mechanism according to claim 1 wherein the gear pairs are ofopposite hand.

5. In a pump, at least one gear set of two gear pairs, the gears of saidpairs having parallel axes, the internal gears ofeach gear set beingrigidly connected together in mutually eccentric relationship. one ofthe external gears being xed in space, and means for imparting to theother of said external gears a circular translation, the external gearsof said pairs having equal pitch circles and the internal gears of saidpairs having equal pitch circles, and the pitch circles of said externalgearsvbearing a relation to the pitch circles of said internal gearssuch that where n is the number of threads of said internal gears, d isthe pitch diameter of said internal gears and D is the pitch diameter ofsaid external gears, and the connection between said internal gearsbeing Such that their orientation with respect to their respectiveexternal gears is the same.

. 6. In a pump, at least three gear sets, all of the gears of said setshaving parallel axes, said gear sets being symmetrically distributedabout the central axis of said pump, the internal gears of each of saidsets being rigidly connected together in eccentric relationship, oneexternal gear of each of said sets being fixed in space, and means forimparting to the other external gears of said sets a circulartranslation, the external gears of said sets having equal pitch circlesand amma- 7 the internal gears of said sets having equal pitch circles,and the pitch circles of said external gears bearing a relation to thepitch circles of said internal gears such that I where n is the numberof threads oi' said internal gears, d is the pitch diameter of saidinternal gears and D is the pitch diameter of said external gears, andthe connection between said internal gears being such that theirorientation with respect to their respective external gears is the Same.

7. In a pump according to claim 6 a drive shaft constituting saidimparting means and having a crank portion, a spider mounted on saidcrank portion, said spider carrying said external gears which are notixed in space.

8. In a pump according to claim 6 a sleeve connecting said externalgears, said rigid connection being enclosed in said sleeve, wherebysaidpump requires no packing glands. l 9. In a pump comprising at leastthree gear `sets wherein all of the gears of said sets have parallelaxes, said sets being symmetrically disfluid-tight sleeve whereby saidpump requireslin packing gland.

10. In a pump according to claim 9 in which said transmitting meanscomprises a number of driving gear pairs, the number of said drivinggear pairs being equal to the number of said sets, the internal gears ofsaid driving gear pairs being constituted by said first mentioned crankmember, and the external gears of said driving gear pairs being mountedon a spider having a bear' ing on the crank portion of said drive shaftwhereby the external gears of the driving pairs are given a movement ofcircular. translation. REN JOSEPH LoUrs MoINnAU.

REFERENCES CITED The following references are of record in the nie ofthis patent:

UNITED STATES PATENTS Number Name Date 1,892,217 Moineau Dec. 27, 19322,028,407 g Moineau Jan. 21, 1936 2,269,189 Dawns Jan. 6, 1942 2,290,137Aldridge July 14, 1942 2,329,386 Brennan Sept. 14, 1943 2,381,695'Sennet Aug. 7, 1945 2,399,008 Doran Apr. 23, 1948 'I FOREIGN PATENTSNumber Country Date 111,901 Australia Nov. 7, 1940 113,009 AustraliaApr. 28, 1941 425,447 Great Britain ,Mar. 14, 1935 Great Britain Oct.18, 1935

